If you have your software firewall set to prevent any network access from Poser then Poser will behave with no apparent slow down (although performance may vary firewall to firewall depending on how efficiently it handles rapid requests). However if you have it set to ask you when Poser tries to access the network, then Poser will ask SO frequently that the firewall is kept in a tight loop shuttling responses back between you and the firewall. Meanwhile Poser does little else between repeated waits for a response from the network/firewall. Above applies to P4 & 5, although the behaviour is a little different between the 2. Poser 5 may have a memory leak or one of it's other many little pissy fits when this happens too, because it seems far less stable afterward. I understand why CL implemented this, and why the check is throughout execution not just at start up, but why do it quite SO frequently that it hurts performance? But then I have lots of "why"s about Poser code ;-)